The present invention relates to a method of assembling a vehicle body of a two-wheeled vehicle by welding a plurality of center members, including a head pipe and cross members of the vehicle body, together with side frames on left and right-hand sides of the vehicle body, and to an assembling apparatus therefor.
There has been known, as disclosed in the Japanese Pat. Publication No. 1182/1981, a method of assembling a two-wheeled vehicle body that uses a center jig for holding center members and a pair of side jigs arranged on the left and right-hand sides for holding the side frames on the left and right-hand sides. The side frames are set on the side jigs in their prostrate positions. The side jigs are then erected on both sides of the center jig, and the center members and the side frames are welded to each other by a plurality of welding torches mounted on the side jigs.
In the above-described prior art method since the side frames assembled after welding a plurality of side frame members together are set on side jigs, a device for assembling the side frames is separately needed. It is also necessary to prepare for each model of machine a plurality of side jigs with welding torches mounted thereon. Such side jigs are complex and expensive. Consequently, the equipment costs are greater as a whole. Furthermore, since the side frames are removed from welding jigs of the side frame assembly device after having been assembled and are then set on the side jigs, there are cases where the side frames become deformed due to welding strains. In addition, since the welding torches are fixed on the side jigs, welding between the side frames and the center members can be effected only by spot welding. This creates a problem that when the vehicle body is transferred onto another jig and final welding is applied, deformation of the body due to welding strains is liable to occur owing to the insufficient weld strength of the spot welds.